1 Field of the Invention
The present invention generally relates to a method for sawing a wafer, and more particularly to a method for manufacturing a semiconductor package by using a multiple-type tape which can prevent the active surface of the wafer from the pollution.
2. Description of the Related Art
The process for manufacturing semiconductor packages generally includes the following steps. First, a wafer is sawn to a plurality of dies. Then, the dies are manufactured to semiconductor packages having a variety of functions. FIGS. 1-6 show that a conventional method for sawing a wafer includes the following steps. First, a wafer which has an active surface and a back surface is provided. Referring to FIG. 1, a grinding tape 20 is attached on the active surface 16 of the wafer 10. Referring to FIG. 2, the back surface 14 of the wafer 10 is grinded by a mechanical grinding device 50. Referring to FIG. 3, a dicing tape 40 is attached on the back surface 14 of the grinded wafer 10, wherein the dicing tape 40 includes a bottom film 42 and a die attach film 44. Referring to FIG. 4, the grinding tape 20 is removed and parted from the active surface 16 of the wafer 10, and the wafer 10 is mounted on a wafer rack 18 by the dicing tape 40. Referring to FIG. 5, the wafer 10 is sawn along the sawing lines 32 by a sawing device so as to separate the dies from one another. Finally, referring to FIG. 6, the sawn die 12 is picked up by a vacuum device 60 so as to finish singularizing the dies 12, wherein the die attach film 44 is still attached on the dies 12. In addition, FIGS. 7 and 8 further show a convention method for manufacturing a semiconductor package. Referring to FIG. 7, the dies 12 including the die attach film 44 is moved and attach to a substrate 70 or a leadframe (not shown) by the vacuum device 60, and the dies 12 is mounted on the substrate 70 by heating the die attach film 44. Referring to FIG. 8, the vacuum device 60 is removed, and the active surface 16 of the wafer 10 is cleaned by a plasma clean process. Finally, a semiconductor package is completely manufactured by a wire bonding process and an encapsulating process.
However, chipping of die easily occurs when the thin wafer is sawn. Furthermore, the chipping can pollute the active surface of the die in the conventional method for sawing the wafer. Thus, it is necessary that the active surface of the wafer is cleaned by the plasma clean process in the convention method for manufacturing semiconductor package. For above reason, the convention method for manufacturing semiconductor package can increase the manufacture time and cost.
Accordingly, there exists a need for a method for sawing a wafer and a method for manufacturing semiconductor package capable of solving the above-mentioned problems.